Hybrid diesel engine cold start control method and related device

Abstract

The invention discloses a hybrid diesel engine cold start control method and a related device, and relates to the field of hybrid diesel engines, and the hybrid diesel engine cold start control method comprises the steps that a motor is controlled to reversely drag an engine at an initial dragging rotating speed, and when the rotating speed of the engine is larger than a rotating speed threshold value, the initial fuel injection quantity of the engine is determined, and fuel injection is conducted; calculating a combustion coefficient in the engine, wherein the combustion coefficient is a parameter representing the combustion degree of fuel oil in the engine; whether the combustion coefficient is larger than a preset threshold value and the torque generated by engine combustion is not smaller than the absolute value of the idle friction torque is judged; and if the combustion coefficient is larger than the preset threshold value and the torque generated by engine combustion is not smaller than the absolute value of the idling friction torque, the motor is controlled to be disengaged from the engine. According to the method, poor fuel oil combustion is prevented through the combustion coefficient, and the motor is disengaged only when the engine can overcome the idling friction torque to maintain operation. Therefore, cold start of the engine in the hybrid diesel engine can be effectively controlled.

Description

Technical Field

[0001] The present application relates to the technical field of hybrid diesel engines, and in particular to a hybrid diesel engine cold start control method and related devices. Background Art

[0002] A hybrid diesel engine is a hybrid power system that combines a diesel engine and an electric motor, using both diesel and the electric motor as a power source to drive the vehicle. When the vehicle is cold-started, the engine can be started by the electric motor or by the engine's own starter.

[0003] When the engine is started by dragging the motor backward, the ECU can control the injection during the startup process to increase the air-fuel ratio in the engine and improve the success rate of the engine's cold start. As long as the motor dragging time is not less than the time setting value, the motor will automatically disengage. Therefore, if the engine itself can maintain idling after the motor is disengaged, the engine cold start is successful, otherwise the engine cold start fails. At the same time, in the process of starting the engine by dragging the motor backward, there may be a problem of poor fuel combustion, which will increase the possibility of engine cold start failure. Therefore, the existing method of starting the engine by dragging the motor backward is difficult to accurately control the cold start of the engine.

[0004] Therefore, how to effectively control the cold start of the engine in a hybrid diesel engine is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above problems, the present application provides a hybrid diesel engine cold start control method and related devices to achieve the purpose of effectively controlling the cold start of the engine in the hybrid diesel engine. The specific scheme is as follows:

[0006] A first aspect of the present application provides a hybrid diesel engine cold start control method, the hybrid diesel engine cold start control method comprising:

[0007] Controlling the motor to reverse the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determining an initial fuel injection amount of the engine and performing fuel injection;

[0008] Calculating a combustion coefficient in the engine, the combustion coefficient being a parameter representing the degree of fuel combustion in the engine;

[0009] Determining whether the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque;

[0010] If the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, the motor is controlled to disengage the engine.

[0011] In a possible implementation, the method further includes:

[0012] If the combustion coefficient is not greater than a preset threshold, or the torque generated by the engine combustion is less than the absolute value of the idle friction torque, the initial fuel injection amount is adjusted according to the combustion coefficient, and the step of calculating the combustion coefficient in the engine is returned to be executed.

[0013] In a possible implementation, adjusting the initial fuel injection amount according to the combustion coefficient includes:

[0014] querying a fuel injection quantity adjustment value corresponding to the combustion coefficient;

[0015] The sum of the fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount, and fuel is injected with the adjusted initial fuel injection amount.

[0016] In a possible implementation, after querying the fuel injection amount adjustment value corresponding to the combustion coefficient, the cold start control method further includes:

[0017] If the battery power SOC of the vehicle is lower than the power threshold, the fuel injection amount adjustment value is corrected according to the SOC to obtain a corrected fuel injection amount adjustment value.

[0018] The step of taking the sum of the fuel injection amount adjustment value and the initial fuel injection amount as the adjusted initial fuel injection amount comprises:

[0019] The sum of the corrected fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount.

[0020] In a possible implementation, the correcting the fuel injection amount adjustment value according to the SOC to obtain the corrected fuel injection amount adjustment value includes:

[0021] A correction coefficient corresponding to the SOC is queried according to the SOC, and a product of the correction coefficient and the fuel injection amount adjustment value is used as the corrected fuel injection amount adjustment value.

[0022] In a possible implementation, the calculating the combustion coefficient in the engine includes:

[0023] determining the heat absorbed by the coolant, the exhaust heat of the engine, the power output of the engine, and the heat of the fuel;

[0024] Calculating the energy sum of the heat absorbed by the coolant, the exhaust heat of the engine, and the output power of the engine;

[0025] The ratio of the total energy to the fuel heat is taken as the combustion coefficient.

[0026] In a possible implementation, determining that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque includes:

[0027] Calculate motor torque;

[0028] Determine the corresponding drag speed friction torque according to the current drag speed of the motor, and obtain the idle friction torque corresponding to the idle speed operation of the engine;

[0029] If the motor torque is not less than a preset difference, it is determined that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque. The preset difference is: the calculation result of the absolute value of the idle friction torque minus the absolute value of the drag speed friction torque. The torque generated by the engine combustion is the sum of the absolute values ​​of the motor torque and the drag speed friction torque.

[0030] A second aspect of the present application provides a hybrid diesel engine cold start control system, the hybrid diesel engine cold start control system comprising:

[0031] A reverse drag unit, used for controlling the motor to reverse the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determining an initial fuel injection amount of the engine and performing fuel injection;

[0032] a calculation unit, used to calculate a combustion coefficient in the engine, wherein the combustion coefficient is a parameter indicating the degree of fuel combustion in the engine;

[0033] a judgment unit, used for judging whether the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, and triggering a control unit if the combustion coefficient is greater than the preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque;

[0034] The control unit is used to control the motor to be disconnected from the engine.

[0035] A third aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:

[0036] The memory is used to store computer programs;

[0037] The processor is used to execute the computer program so that the electronic device can implement the hybrid diesel engine cold start control method of the first aspect or any implementation of the first aspect.

[0038] The fourth aspect of the present application provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the hybrid diesel engine cold start control method of the first aspect or any implementation of the first aspect.

[0039] By means of the above technical scheme, the present application provides a hybrid diesel engine cold start control method and related devices. The method first controls the motor to reverse the engine at an initial drag speed. When the engine speed is greater than the speed threshold, the initial fuel injection amount of the engine is determined and the fuel is injected. Then the combustion coefficient inside the engine is calculated to determine whether the combustion coefficient is greater than the preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque. If all are satisfied, the motor can be disengaged. The method adjusts the initial fuel injection amount according to the calculated combustion coefficient inside the engine, controls the fuel combustion inside the engine, effectively prevents poor fuel combustion, and when the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, it indicates that the torque generated by the engine combustion can maintain idle operation. When the motor is disengaged, the engine can overcome the idle friction torque to maintain operation. Therefore, the method can effectively control the cold start of the engine in the hybrid diesel engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0041] Figure 1 A schematic flow chart of a hybrid diesel engine cold start control method provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of a hybrid diesel engine cold start control method provided in an embodiment of the present application;

[0043] Figure 3 A hardware structure block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0045] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0046] The terms "first", "second" etc. in the specification of the application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable in appropriate circumstances, and this is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0047] A hybrid diesel engine is a hybrid power system that combines a diesel engine and an electric motor. It can be divided into P0, P1, P2, P3 and P4 according to the position of the motor. Among them, the motors of P0, P1 and P2 configurations can be directly connected to the engine, so the engine can be started by reverse dragging the motor.

[0048] When the vehicle is cold started (ambient temperature is generally below -15℃, and can be as low as -40℃), the fuel atomization of the hybrid diesel engine is poor in a low temperature environment, and the compression temperature in the engine cylinder is low, making it difficult for the fuel to burn. Therefore, other methods can be used to assist the engine start. Specifically, the engine can be started by reverse dragging the motor or by the engine's own starter.

[0049] When the engine is started by reverse dragging at a higher drag speed by the motor, the ECU injects fuel according to the engine speed to improve the success rate of the engine's cold start. Since the time setting value is set for the motor to reverse the engine, when the motor's reverse drag time reaches the time setting value, the motor will automatically disengage, and after the motor is disengaged, if the engine can maintain idling by itself, the engine cold start is successful, otherwise the engine cold start fails. The method of reverse dragging the engine for cold start does not interact with the engine, but unilaterally controls the motor with the time setting value. Therefore, the method of reverse dragging the engine for cold start has the possibility of cold start failure, and during the reverse dragging process, there may also be problems with poor fuel combustion, which will increase the possibility of engine cold start failure. Furthermore, when the motor reverses the engine at a higher speed, the engine is prone to mechanical wear.

[0050] When the engine is started by the starter motor at a low speed, a longer start time is required due to the low compression temperature in the engine cylinder. However, due to the excessive current when the engine is started, the starter motor cannot be used for too long. Therefore, the cold start failure rate of the starter motor is high. In order to reduce the cold start failure rate, the fuel injection amount during the start process needs to be increased. However, the increase in fuel injection amount is likely to lead to poor fuel combustion, produce more soot and clog the downstream DPF (Diesel Particulate Filter).

[0051] In summary, both the starting methods of starting the engine by reverse dragging the motor and starting the engine by the starter built into the engine have disadvantages. Therefore, how to effectively control the cold start of the engine in the hybrid diesel engine.

[0052] In order to solve the above problems, an embodiment of the present application provides a hybrid diesel engine cold start control method. In this method, the motor reverses the engine at an initial drag speed, and when the engine speed is greater than the speed threshold, fuel injection is performed to improve the cold start success rate of the engine. After fuel injection, the combustion coefficient in the engine is calculated in real time, and the fuel combustion inside the engine is controlled by the combustion coefficient to effectively prevent poor fuel combustion. The current condition of the engine is determined by judging the combustion coefficient and the torque generated by the engine combustion. After determining that the engine cold start is successful, the motor is controlled to disengage. The hybrid diesel engine cold start control method of the embodiment of the present application is described in detail below in conjunction with the accompanying drawings.

[0053] Reference Figure 1 , Figure 1 A flow chart of a hybrid diesel engine cold start control method provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, a data processing method provided in an embodiment of the present application may include steps S10 to S13, and these steps are described in detail below.

[0054] S10, controlling the motor to reversely drag the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determining an initial fuel injection amount of the engine, and performing fuel injection.

[0055] The initial drag speed can be obtained by querying the oil temperature, which is a relatively low speed, and its value can be 100r / min. The speed threshold is the engine injection speed. Only when the engine speed is greater than the speed threshold, the temperature and pressure in the engine combustion chamber are high enough, and the fuel injected into the engine cylinder can be burned. The speed threshold can be between 100r / min and 200r / min.

[0056] In order to reduce the mechanical wear of the motor on the engine during the reverse towing process, this embodiment chooses to establish oil pressure during the reverse towing process of the motor to reduce mechanical wear. The oil pressure is the driving force for the oil to flow inside the engine, which can ensure that the oil can smoothly reach all lubrication points of the engine and provide necessary lubrication for various parts of the engine. When the oil pressure is normal, the oil can form a uniform oil film to protect the parts from direct contact and mechanical wear.

[0057] Specifically, the present embodiment controls the motor to first reverse the engine at a relatively low initial drag speed, and gradually increases the drag speed. Since the oil pressure is positively correlated with the drag speed, the corresponding relationship can be shown in Table 1. Therefore, when the drag speed of the motor gradually increases, the oil pressure also gradually increases. Since the oil is viscous and has poor fluidity in a low temperature environment, the oil pressure has a gradual establishment process of about 3-8 seconds. During the gradual establishment of the oil pressure, the oil pressure can limit the increase rate of the motor drag speed, and prevent the motor drag speed from increasing too quickly before the oil pressure is established, causing mechanical wear of the engine. When the oil pressure is greater than P0, it can be considered that the oil pressure has been established.

[0058] Table 1

[0059]

[0060] As the motor's drag speed gradually increases, the engine speed also gradually increases. Therefore, when the engine speed is greater than the speed threshold, the initial fuel injection amount can be determined based on the engine's coolant temperature and the engine's exhaust temperature. The corresponding relationship between the coolant temperature, the exhaust temperature and the initial fuel injection amount can be shown in Table 2:

[0061] Table 2

[0062]

[0063] The coolant temperature can be measured by a temperature sensor, and the exhaust temperature can be measured by an exhaust temperature sensor or a temperature sensor before a DOC (Diesel Oxidation Catalyst). After the initial injection amount is determined, the control is to inject fuel into the engine at the initial injection amount per second.

[0064] S11. Calculate the combustion coefficient in the engine, where the combustion coefficient is a parameter indicating the degree of fuel combustion in the engine.

[0065] Among them, the energy generated by the combustion of fuel after it is injected into the engine, its energy consumption can mainly be: the heat absorbed by the coolant, the exhaust heat, the output power of the engine (the work done to overcome the friction torque) and other losses (a small proportion, which can be ignored). Therefore, the greater the sum of the energy of the heat absorbed by the coolant, the exhaust heat, and the output power of the engine, the more complete the fuel combustion inside the engine, otherwise it means that the combustion is worse. Therefore, in this embodiment, the ratio of the sum of the energy of the heat absorbed by the coolant, the exhaust heat, and the output power of the engine to the heat of the fuel is defined as the combustion coefficient.

[0066] Specifically, the specific process of calculating the combustion coefficient in this embodiment can be shown as steps 1 to 3:

[0067] Step 1: Determine the heat absorbed by the coolant, the exhaust heat of the engine, the engine output power and the fuel heat;

[0068] Step 2: Calculate the total energy of the heat absorbed by the coolant, the exhaust heat of the engine and the output power of the engine;

[0069] Step 3: The ratio of the total energy to the fuel heat is taken as the combustion coefficient.

[0070] The heat absorbed by the coolant can be calculated and determined based on the temperature change of the coolant and the specific heat capacity of the coolant, and the exhaust heat of the engine can be calculated and determined based on the temperature change of the exhaust and the specific heat capacity of the coolant. The power of the engine can be calculated in real time based on the friction torque of the engine and the motor torque, and the output power of the engine is the cumulative value of the power of the engine during the fuel combustion process. The heat of the fuel can be calculated based on the calorific value of the fuel and the injection amount. The calorific value of the fuel is the heat generated by the complete combustion of the fuel per unit weight, and the injection amount is the current injection amount of the engine. In this embodiment, the fuel type is diesel.

[0071] Taking the diesel combustion process from time t0 to time t1 as an example, the calculation formulas for the heat absorbed by the coolant, the exhaust heat of the engine, the power of the engine and the heat of the fuel in this embodiment can be as follows:

[0072] Heat absorbed by coolant = (coolant temperature at time t1 - coolant temperature at time t0) × specific heat capacity of coolant;

[0073] Engine exhaust heat = (exhaust temperature at time t1 - exhaust temperature at time t0) × coolant specific heat capacity;

[0074] Engine power = [(|friction torque of diesel engine| + motor torque) × speed] / 9550;

[0075] Fuel calorific value = diesel calorific value × fuel injection amount;

[0076] Among them, the temperature of the coolant before and after and the temperature of the exhaust before and after can be obtained through temperature sensors, the specific heat capacity of the coolant can be directly obtained by looking up the table, and the injection amount is the total injection amount from time t0 to time t1, which can be obtained through engine measurement.

[0077] This embodiment uses the ratio of the total energy to the fuel heat as the combustion coefficient. Specifically, this embodiment can use the total energy as the numerator and the fuel heat as the denominator. The larger the combustion coefficient, the greater the proportion of the total energy of the heat absorbed by the coolant, the exhaust heat, and the output power of the engine in the total heat generated by the fuel combustion, and the more complete the combustion of the fuel inside the engine; the smaller the combustion coefficient, the worse the combustion of the fuel inside the engine.

[0078] Of course, in this embodiment, the total energy can also be used as the denominator and the fuel heat as the numerator. Then, when the combustion coefficient is smaller, it means that the total energy of the heat absorbed by the coolant, the exhaust heat, and the output power of the engine accounts for a larger proportion of the total heat generated by the fuel combustion, and the fuel burns more completely inside the engine; when the combustion coefficient is larger, it means that the fuel burns worse inside the engine.

[0079] S12, determining whether the combustion coefficient is greater than a preset threshold and the torque generated by engine combustion is not less than the absolute value of the idle friction torque;

[0080] S13: If the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, the motor is controlled to disengage the engine.

[0081] The preset threshold is the limit value of the combustion coefficient. In this embodiment, the preset threshold value may be 0.7. Idle friction torque refers to the torque generated by the friction between the internal parts of the engine when the engine is in an idle condition (the engine is running without load). The idle friction torque can consume a part of the output power of the engine.

[0082] Specifically, this embodiment mainly determines whether the torque generated by engine combustion is not less than the absolute value of the idle friction torque by the magnitude of the motor torque. The specific process can be shown in steps 4 to 6:

[0083] Step 4: Calculate the motor torque;

[0084] Step 5: Determine the corresponding drag speed friction torque according to the current drag speed of the motor, and obtain the idle friction torque corresponding to the engine idling;

[0085] Step 6: If the motor torque is not less than the preset difference, it is determined that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque.

[0086] Among them, the motor torque can be calculated based on the motor speed and the motor output power. The preset difference is: the absolute value of the idle friction torque minus the absolute value of the drag speed friction torque. The drag speed friction torque is the friction torque between the transmission components when the motor drags the engine. Both the idle friction torque and the drag speed friction torque can be determined by the speed. The speed under idle conditions is generally a fixed value, and the drag speed friction torque can be determined by the speed of the motor dragging the engine. The corresponding relationship between the speed and the friction torque can be shown in Table 3:

[0087] Table 3

[0088]

[0089] The torque generated by engine combustion is the sum of the absolute value of the motor torque and the drag speed friction torque. When the engine can maintain idling operation, the torque generated by engine combustion is greater than the idling friction torque. Therefore, when the motor torque is not less than the absolute value of the idling friction torque minus the absolute value of the drag speed friction torque, it means that the engine can maintain idling operation. Specifically, it can be expressed as follows through the formula:

[0090] The torque generated by engine combustion - |idle friction torque|≥0, indicating that the engine itself can maintain idle operation;

[0091] Torque generated by engine combustion = | drag speed friction torque | + motor torque;

[0092] Then |Drag speed friction torque|+motor torque-|idle speed friction torque|≥0;

[0093] Therefore, when the motor torque ≥ |idle friction torque|-|drag speed friction torque|, it means that the engine itself can maintain idle operation.

[0094] For example, when the idle speed is 600r / min, the motor reverse drag engine start speed is 800r / min, and the motor torque is 6Nm, according to Table 4, the idle friction torque is -48, and the drag speed friction torque is -42. Since the motor torque is not less than the absolute value of the idle friction torque minus the absolute value of the drag speed friction torque (6≥|-48|-|-42|), it is determined that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, indicating that the engine itself can maintain idle operation at this time.

[0095] Furthermore, if the current moment when the fuel injection is performed with the initial fuel injection amount, the combustion coefficient calculated at the current moment is greater than the preset threshold value and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, then the motor can be controlled to disengage the engine at this time, and the engine is controlled by the ECU. If the current moment when the fuel injection is performed with the initial fuel injection amount, the combustion coefficient is not greater than the preset threshold value, or the torque generated by the engine combustion is less than the absolute value of the idle friction torque, the initial fuel injection amount needs to be adjusted according to the combustion coefficient, and the fuel injection is performed according to the adjusted initial fuel injection amount at the next moment, and it is re-determined whether the combustion coefficient is greater than the preset threshold value and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque.

[0096] Furthermore, the initial fuel injection amount adjusted according to the combustion coefficient should not exceed the maximum fuel injection amount (external characteristic fuel injection amount) at the current engine speed. The maximum fuel injection amount has been preset in the ECU in advance, and the maximum fuel injection amount of different engines at the same speed is different. Specifically, when the adjusted initial fuel injection amount is less than the maximum fuel injection amount at the current engine speed, the fuel injection is carried out according to the adjusted initial fuel injection amount; when the adjusted initial fuel injection amount is equal to the maximum fuel injection amount at the current engine speed, the fuel injection is carried out according to one of them; when the adjusted initial fuel injection amount is greater than the maximum fuel injection amount at the current engine speed, the fuel injection is carried out according to the maximum fuel injection amount at the current engine speed.

[0097] Specifically, the specific process of adjusting the initial fuel injection amount according to the combustion coefficient in this embodiment can be shown in steps 7 and 8:

[0098] Step 7: Query the fuel injection amount adjustment value corresponding to the combustion coefficient;

[0099] Step 8: The sum of the fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount, and fuel is injected with the adjusted initial fuel injection amount.

[0100] Among them, the corresponding relationship between the combustion coefficient and the injection amount adjustment value can be shown in Table 4:

[0101] Table 4

[0102]

[0103] When the combustion coefficient is large, it means that the combustion condition in the engine is better, and the injection amount adjustment value can be increased based on the initial injection amount; when the combustion coefficient is small, it means that the combustion condition in the engine is poor, and the injection amount adjustment value can be subtracted based on the initial injection amount to prevent poor fuel combustion from producing carbon smoke and clogging the DPF.

[0104] When the battery level of the vehicle is low, the engine will automatically charge the battery while providing power. Therefore, in order to ensure that the engine can still be successfully cold-started under low battery conditions, this embodiment determines the fuel injection amount adjustment value based on the combustion coefficient query. If the vehicle is in a low battery state, the fuel injection amount adjustment value needs to be corrected according to the vehicle's SOC (State of Charge). Specifically, if the vehicle's battery SOC is not lower than the battery threshold, the fuel injection amount adjustment value is not corrected; if the vehicle's battery SOC is lower than the battery threshold, the fuel injection amount adjustment value is corrected according to the SOC, and the sum of the corrected fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount. In this embodiment, the battery threshold is 10%.

[0105] Among them, this embodiment can query the correction coefficient corresponding to the SOC according to the SOC, and use the product of the correction coefficient and the injection amount adjustment value as the corrected injection amount adjustment value. Of course, this embodiment can also directly construct a corresponding relationship table between the SOC and the injection amount adjustment value, so as to directly query and obtain the injection amount adjustment value corresponding to the SOC. The corresponding relationship table between the SOC and the correction coefficient can be shown in Table 5:

[0106] Table 5

[0107]

[0108] Of course, after the SOC corrects the injection amount adjustment value, the adjusted initial injection amount should also not exceed the maximum injection amount at the current engine speed. The smaller injection amount is selected between the adjusted initial injection amount and the maximum injection amount at the current engine speed as the injection amount at the current moment, and injection is performed; when the adjusted initial injection amount is equal to the maximum injection amount at the current engine speed, injection is performed according to one of the injection amounts.

[0109] As the amount of fuel injected increases, the torque output by the engine combustion also increases synchronously, while the drag torque of the motor gradually decreases.

[0110] The embodiment of the present application provides a cold start control method, which first controls the motor to reverse the engine at an initial drag speed. When the engine speed is greater than the speed threshold, the initial fuel injection amount of the engine is determined, and then the combustion coefficient inside the engine is calculated and fuel is injected to determine whether the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque. If all are satisfied, the motor can be disengaged. This method adjusts the initial fuel injection amount according to the calculated combustion coefficient inside the engine, controls the fuel combustion inside the engine, and effectively prevents poor fuel combustion and excessive smoke. When the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, it means that the torque generated by the engine combustion can maintain idle operation. In the case of the motor being disengaged, the engine can overcome the idle friction torque to maintain operation. Therefore, this method can effectively control the cold start of the engine in a hybrid diesel engine.

[0111] A hybrid diesel engine cold start control method provided by an embodiment of the present application is introduced above, and a system applying the hybrid diesel engine cold start control method will be introduced below.

[0112] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a hybrid diesel engine cold start control system provided in an embodiment of the present application. Figure 2 As shown, the hybrid diesel engine cold start control system includes:

[0113] The reverse drag unit 100 is used to control the motor to reverse the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determine the initial fuel injection amount of the engine and perform fuel injection;

[0114] The calculation unit 110 is used to calculate the combustion coefficient in the engine, where the combustion coefficient is a parameter indicating the degree of fuel combustion in the engine;

[0115] The judging unit 120 is used to judge whether the combustion coefficient is greater than a preset threshold value and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, and if the combustion coefficient is greater than the preset threshold value and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, the control unit 130 is triggered;

[0116] The control unit 130 is used to control the motor to be disconnected from the engine.

[0117] In a possible implementation, the hybrid diesel engine cold start control system may further include an adjustment unit:

[0118] The adjustment unit is used to adjust the initial fuel injection amount according to the combustion coefficient when the combustion coefficient is not greater than a preset threshold, or the torque generated by the engine combustion is less than the absolute value of the idle friction torque, and return to the trigger calculation unit 110.

[0119] In a possible implementation, the adjusting unit adjusts the initial fuel injection amount according to the combustion coefficient, which may specifically include:

[0120] A query subunit, used to query the fuel injection amount adjustment value corresponding to the combustion coefficient;

[0121] The fuel quantum unit is used to take the sum of the fuel injection amount adjustment value and the initial fuel injection amount as the adjusted initial fuel injection amount, and inject fuel with the adjusted initial fuel injection amount.

[0122] In a possible implementation, after executing the above query subunit, the hybrid diesel engine cold start control system may further include:

[0123] The correction unit is used to correct the fuel injection amount adjustment value according to the SOC when the battery power SOC of the vehicle is lower than the power threshold, so as to obtain the corrected fuel injection amount adjustment value.

[0124] The above oil quantum unit can be specifically configured as follows:

[0125] The sum of the corrected fuel injection amount adjustment value and the initial fuel injection amount is taken as the adjusted initial fuel injection amount.

[0126] In a possible implementation, the correction unit may be specifically configured as follows:

[0127] The correction coefficient corresponding to the SOC is queried according to the SOC, and the product of the correction coefficient and the injection quantity adjustment value is used as the corrected injection quantity adjustment value.

[0128] In a possible implementation, the computing unit 110 may be specifically configured as follows:

[0129] Determine the heat absorbed by the coolant, the exhaust heat of the engine, the output power of the engine and the heat of the fuel, calculate the total energy of the heat absorbed by the coolant, the exhaust heat of the engine and the output power of the engine, and take the ratio of the total energy to the heat of the fuel as the combustion coefficient.

[0130] In a possible implementation, the judging unit 120 judges whether the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, which can be specifically configured as follows:

[0131] The motor torque is calculated, the corresponding drag speed friction torque is determined according to the current drag speed of the motor, and the idle friction torque corresponding to the engine idling is obtained. If the motor torque is not less than the preset difference, it is determined that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque. The preset difference is: the absolute value of the idle friction torque minus the calculation result of the absolute value of the drag speed friction torque. The torque generated by the engine combustion is the sum of the absolute values ​​of the motor torque and the drag speed friction torque.

[0132] The present application also provides an electronic device in an embodiment. Figure 3 As shown, it shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiment of the present application. The electronic device in the embodiment of the present application may include but is not limited to fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, etc. Figure 3 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0133] like Figure 3 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage device 308 to a random access memory (RAM) 303. When the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 303. The processing device 301, the ROM 302, and the RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0134] Typically, the following devices may be connected to the I / O interface 305: an input device 306 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 307 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 308 including, for example, a memory card, a hard disk, etc.; and a communication device 309. The communication device 309 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 3 An electronic device having various devices is shown, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.

[0135] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any hybrid diesel engine cold start control method provided in the embodiment of the present application.

[0136] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any hybrid diesel engine cold start control method provided in the embodiment of the present application.

[0137] It should also be noted that the system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the system embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

[0138] Through the description of the above implementation mode, the technicians in the field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation mode in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, a U disk, a mobile hard disk, a ROM, a RAM, a disk or an optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, a training device, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0139] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0140] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, training device, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0141] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0142] It is understandable that before using the technical solutions disclosed in the embodiments of the present disclosure, the types, scope of use, usage scenarios, etc. of the personal information involved in the present disclosure should be informed to the user and the user's authorization should be obtained in an appropriate manner in accordance with relevant laws and regulations.

[0143] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A hybrid diesel engine cold start control method, characterized in that: The hybrid diesel engine cold start control method comprises: Controlling the motor to reverse the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determining an initial fuel injection amount of the engine and performing fuel injection; Calculating a combustion coefficient in the engine, the combustion coefficient being a parameter representing the degree of fuel combustion in the engine; Determining whether the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque; If the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, the motor is controlled to disengage the engine.

2. The hybrid diesel engine cold start control method according to claim 1, characterized in that: Also includes: If the combustion coefficient is not greater than a preset threshold, or the torque generated by the engine combustion is less than the absolute value of the idle friction torque, the initial fuel injection amount is adjusted according to the combustion coefficient, and the step of calculating the combustion coefficient in the engine is returned to be executed.

3. The hybrid diesel engine cold start control method according to claim 2, characterized in that: The adjusting the initial fuel injection amount according to the combustion coefficient comprises: querying a fuel injection quantity adjustment value corresponding to the combustion coefficient; The sum of the fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount, and fuel is injected with the adjusted initial fuel injection amount.

4. The hybrid diesel engine cold start control method according to claim 3, characterized in that: After querying the fuel injection amount adjustment value corresponding to the combustion coefficient, the cold start control method further includes: If the battery power SOC of the vehicle is lower than the power threshold, the fuel injection amount adjustment value is corrected according to the SOC to obtain a corrected fuel injection amount adjustment value. The step of taking the sum of the fuel injection amount adjustment value and the initial fuel injection amount as the adjusted initial fuel injection amount comprises: The sum of the corrected fuel injection amount adjustment value and the initial fuel injection amount is used as the adjusted initial fuel injection amount.

5. The hybrid diesel engine cold start control method according to claim 4, characterized in that: The step of correcting the fuel injection amount adjustment value according to the SOC to obtain a corrected fuel injection amount adjustment value includes: A correction coefficient corresponding to the SOC is queried according to the SOC, and a product of the correction coefficient and the fuel injection amount adjustment value is used as the corrected fuel injection amount adjustment value.

6. The hybrid diesel engine cold start control method according to claim 1, characterized in that: The calculating the combustion coefficient in the engine comprises: determining the heat absorbed by the coolant, the exhaust heat of the engine, the power output of the engine, and the heat of the fuel; Calculating the energy sum of the heat absorbed by the coolant, the exhaust heat of the engine, and the output power of the engine; The ratio of the total energy to the fuel heat is taken as the combustion coefficient.

7. The hybrid diesel engine cold start control method according to claim 1, characterized in that: Determining that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque includes: Calculate motor torque; Determine the corresponding drag speed friction torque according to the current drag speed of the motor, and obtain the idle friction torque corresponding to the idle speed operation of the engine; If the motor torque is not less than a preset difference, it is determined that the torque generated by the engine combustion is not less than the absolute value of the idle friction torque. The preset difference is: the calculation result of the absolute value of the idle friction torque minus the absolute value of the drag speed friction torque. The torque generated by the engine combustion is the sum of the absolute values ​​of the motor torque and the drag speed friction torque.

8. A hybrid diesel engine cold start control system, characterized in that: The hybrid diesel engine cold start control system comprises: A reverse drag unit, used for controlling the motor to reverse the engine at an initial drag speed, and when the engine speed is greater than a speed threshold, determining an initial fuel injection amount of the engine and performing fuel injection; a calculation unit, used to calculate a combustion coefficient in the engine, wherein the combustion coefficient is a parameter indicating the degree of fuel combustion in the engine; a judgment unit, used for judging whether the combustion coefficient is greater than a preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque, and triggering a control unit if the combustion coefficient is greater than the preset threshold and the torque generated by the engine combustion is not less than the absolute value of the idle friction torque; The control unit is used to control the motor to be disconnected from the engine.

9. An electronic device, characterized in that: The method comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the hybrid diesel engine cold start control method as described in any one of claims 1 to 7.

10. A computer program product, characterized in that It comprises computer-readable instructions, and when the computer-readable instructions are executed on an electronic device, the electronic device implements the hybrid diesel engine cold start control method as claimed in any one of claims 1 to 7.

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